To elucidate the roles of RRM2 in PCa progression, we first detected the expression of RRM2 in different PCa cells (Fig. 4A, B), to silence or regain the expression of RRM2 with higher efficiencies, as well as providing reliable conclusion through validating the function of RRM2 in two cell lines, we chose the two cell lines with moderate RRM2 expression, PC3 and DU145,to perform further functional assays and transfected two independent siRNAs to knockdown RRM2 in PCa cells (Fig. 4C). Here, RRM2 is linked to posterior cortical atrophy.